diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/layout/pack-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/layout/pack-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,67 @@
+require("../env");
+require("../../d3");
+require("../../d3.layout");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.layout.pack");
+
+suite.addBatch({
+  "pack": {
+    topic: d3.layout.pack,
+    "can handle an empty children array": function(pack) {
+      assert.deepEqual(pack.nodes({children: [{children: []}, {value: 1}]}).map(layout), [
+        {value: 1, depth: 0, x: 0.5, y: 0.5, r: 0.5},
+        {value: 0, depth: 1, x: 0.0, y: 0.5, r: 0.0},
+        {value: 1, depth: 1, x: 0.5, y: 0.5, r: 0.5}
+      ]);
+    },
+    "can handle zero-valued nodes": function(pack) {
+      assert.deepEqual(pack.nodes({children: [{value: 0}, {value: 1}]}).map(layout), [
+        {value: 1, depth: 0, x: 0.5, y: 0.5, r: 0.5},
+        {value: 0, depth: 1, x: 0.0, y: 0.5, r: 0.0},
+        {value: 1, depth: 1, x: 0.5, y: 0.5, r: 0.5}
+      ]);
+    },
+    "can handle residual floating point error": function(pack) {
+      var result = pack.nodes({children: [
+        {value: 0.005348322447389364},
+        {value: 0.8065882022492588},
+        {value: 0}
+      ]}).map(layout);
+      assert.isFalse(result.map(function(d) { return d.depth; }).some(isNaN));
+      assert.isFalse(result.map(function(d) { return d.value; }).some(isNaN));
+      assert.isFalse(result.map(function(d) { return d.x; }).some(isNaN));
+      assert.isFalse(result.map(function(d) { return d.y; }).some(isNaN));
+      assert.isFalse(result.map(function(d) { return d.r; }).some(isNaN));
+    },
+    "avoids coincident circles": function(pack) {
+      var result = pack({children: [
+        {children: [{value: 17010}, {value: 5842}, {value: 0}, {value: 0}]},
+        {children: [
+          {children: [{value: 721}, {value: 4294}, {value: 9800}, {value: 1314}, {value: 2220}]},
+          {value: 1759}, {value: 2165}, {value: 586}, {value: 3331}, {value: 772}, {value: 3322}
+        ]}
+      ]}).map(layout);
+      result.sort(function(a, b) {
+        return a.x < b.x && a.y < b.y ? -1 : 1;
+      });
+      assert.isFalse(result.slice(1).some(function(d, i) {
+        return d.x === result[i].x && d.y === result[i].y && d.value > 0;
+      }));
+    }
+  }
+});
+
+function layout(node) {
+  return {
+    value: node.value,
+    depth: node.depth,
+    r: node.r,
+    x: node.x,
+    y: node.y
+  };
+}
+
+suite.export(module);